android应用开发揭秘examples_04-12笔记(Button的使用)

演示效果：



前面例子几乎每一个都有button,所以这里也不多解释了，上代码：

package com.yarin.android.Examples_04_12;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class Activity01 extends Activity
{
//声明按钮
Button m_Button1,m_Button2;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

//取得Button对象
m_Button1=(Button)findViewById(R.id.Button1);
m_Button2=(Button)findViewById(R.id.Button2);

//设置按钮嗦显示的文字
m_Button1.setText("开始");
m_Button2.setText("退出");

//设置按钮的宽度
m_Button1.setWidth(150);
m_Button2.setWidth(100);

//设置文字的颜色
m_Button1.setTextColor(Color.GREEN);
m_Button2.setTextColor(Color.RED);

//设置文字的大小尺寸
m_Button1.setTextSize(30);
m_Button2.setTextSize(20);

//m_Button1.setBackgroundColor(Color.BLUE);

//设置按钮的事件监听
m_Button1.setOnClickListener(new Button.OnClickListener(){
public void onClick(View v)
{
//处理按钮事件
//产生一个Toast
//m_Button1.getText()得到按钮显示的内容
Toast toast = Toast.makeText(Activity01.this, "你点击了“"+m_Button1.getText()+"”按钮！", Toast.LENGTH_LONG);
//设置toast显示的位置
toast.setGravity(Gravity.TOP, 0, 150);
//显示该Toast
toast.show();
}
});

m_Button2.setOnClickListener(new Button.OnClickListener(){
public void onClick(View v)
{
//处理按钮事件
Activity01.this.finish();
}
});
}
}

------------------------ main.xml ---------------------------------
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:id="@+id/TextView1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<Button
android:id="@+id/Button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
</Button>
<Button
android:id="@+id/Button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
>
</Button>
</LinearLayout>